


Swapped

by Kien Rugastelo (cein)



Category: Tsubasa: Reservoir Chronicle
Genre: Body Dysphoria, Bodyswap, Chronic Pain, M/M, Trans!Kurogane
Language: English
Status: Completed
Published: 2020-08-26
Updated: 2020-08-26
Packaged: 2021-03-07 01:13:28
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 9,799
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26128585
Author URL: https://archiveofourown.org/users/cein/pseuds/Kien%20Rugastelo
Summary: Kurogane, Fai, Mokona, and Syaoran land in a world with their souls in the wrong bodies. When they find that accessing their magic is harder than they thought, it takes some creative thinking to move them on to the next world.
Relationships: Fay D. Fluorite/Kurogane
Comments: 3
Kudos: 35





	Swapped

**Author's Note:**

> This fic exists in a separate universe from "Building a Child".

Kurogane’s first impression of the landing was that it was rough, but he was grateful not to be the bottom of the pile for once. Actually, though he could feel the ground below him, there was no one on top of him, either. If he opened his eyes to find they were all separated, he’d have to kill the manjuu for real this time. Still a little dazed and feeling strangely light, he opened his eyes to see himself lying in the grass a few feet away.

Startled, he yelped and sat straight up, and his voice was higher than it should have been. The body —  _ his _ body lying near him hadn’t moved yet. He looked down, finding a familiar white cloak and black boots, and when he lifted his hands, they were pale, thin, and the fingertips scarred. He felt his chest, and it was whole. Those hands registered the sensation, though no feeling came from the fingertips. This was Fai’s body. And if he was in Fai’s body, then maybe it was Fai in his. He hoped it wasn’t Fai in his. He hoped it  _ was _ Fai in his. The thought of having anyone but himself in his own body stirred up feelings of violation that made him want to be ill in the grass, but if there was someone in there right now who wasn’t Fai — he didn’t even want to consider it.

He began breathing harshly, a reaction he wasn’t familiar with but the body began having all the same, and across from him, his body finally opened its eyes, expression wide in a way he wasn’t used to seeing on his own face, and the voice croaked out, uncertain as the flesh hand reached forward: “Fai?”

Kurogane shook his head roughly, breathing evening out a bit as if seeing someone else on the verge of panic somehow allowed him to back down from that precipice himself. “Kurogane.”

His body shook his head in almost the exact same way, denial and bewilderment present on that face. “No, I’m not — ”

“ _ I’m _ Kurogane,” he stressed, correcting the misunderstanding.

“You’re..?” his body started, only just now registering the hand in the line of vision. Whoever it was only inspected the hand a moment before looking lower, patting the body down frantically as if scrambling to reach a comprehension. Kurogane felt alien seeing the borderline panic on his own face. “I’m in your body,” he breathed.

“Fai?” Kurogane chanced. The body, Fai occupying it, nodded. “What’s going — ?”

“Fai-san! Kurogane-san!” Mokona’s voice rang out, and they both whipped their heads around to see Syaoran and Mokona coming over the short hill, Syaoran nearly bouncing instead of running. Kurogane had a sinking feeling that he understood why, and when the pair finished traversing the short distance, it was “Mokona” who spoke again. “Are you..?”

“Yeah,” Kurogane answered for them both, Fai still looking as though he had seen a ghost. He never thought he’d see his own body looking so pale, and he’d seen how he looked after the massive blood loss associated with severing his own arm. “And you?”

“Mokona is Syaoran!” “Syaoran”’s voice rang out, pitched oddly high, “And Syaoran is Mokona!”

“This,” Fai began haltingly, finally beginning to return to the present, “Is not ideal.”

* * *

It was decided the first order of business would be survival: shelter, food, and water. Everything else could be figured out after. Luckily, there was a town nearby that didn’t even seem to understand currency as a concept — and Kurogane was not about to look that gift horse in the mouth. Syaoran had not been able to use whatever magic Mokona employed to access their storage, and so they would not have had much of anything to trade. Instead, they were offered lodging at the local inn, run by a Yukito and a Touya who seemed to be switched out and comfortable in it as if they had been born that way, just as the rest of them were.

They separated into their two rooms to settle in for a moment, and that was when Fai spoke up. “The good news is that it seems that’s just how this world is.”

“That’s good news?” Kurogane asked with more than a little doubt.

Fai nodded, closing the drawer now that Kurogane’s cloak was in there. This world was a warm one, and Fai had still only barely glanced his way. “It means when we leave, we should be switched back.”

That was good news, Kurogane supposed. “And the bad news?”

Fai looked grave. “Syaoran-kun can’t use Mokona’s magic, and you don’t know how to use mine. Until we figure out each other’s bodies, we’ll be stuck here.”

So Syaoran would have to figure out Mokona’s magic, or Kurogane would have to figure out Fai’s, Kurogane reasoned. There was a chance Syaoran’s body had enough magic as well, so there was the possibility of Mokona learning enough human magic for Syaoran’s body to use the one-time chance of crossing worlds on its own. Kurogane doubted his own body had enough magic to make the trip possible. The outlook wasn’t good. With anybody else in Fai’s body, they would have stood a better chance, or if Fai had landed in any other body — but then Syaoran or Mokona would be in his, and Kurogane couldn’t stand the thought of it.

“I’m sorry, Kuro-tan,” Fai continued.

Kurogane was sure the way he crossed his arms and frowned was not very Fai-like at all. “What for?”

“This,” Fai said, indicating the body he was in with a vague wave. “For what it’s worth, you can do anything with my body that we’ve done together. You have my permission. But you should tell me what I should and shouldn’t do with yours.”

Kurogane knew what Fai was saying in what he was not. They’d fallen into bed together often enough for Fai to know that while Kurogane no longer had his breasts, he still had dysphoria in regards to his genitals. He’d made his peace with them, but they were still not quite “right”, and there was a space there that he didn’t like to acknowledge, much less use. Fai was giving him the gift of experiencing Fai’s body in the ways his own hadn’t been configured, and trying to be considerate in turn. He’d feel more grateful if Fai could bear to look at him. “Do what you want.”

“I wouldn’t want to do anything to it you wouldn’t do,” Fai answered, almost like he was trying to bargain with him.

It grated on him. “Just don’t use.. that,” he ground out. “Everything else is fine.”

“Okay,” Fai said, not sounding thoroughly convinced. “I should warn you, when emotions run high, you’ll probably get cravings,” he added delicately. “If that happens, we can — ”

“I’m not drinking your blood,” Kurogane cut in.

“Okay,” Fai said again, with just as much conviction as before. He still wouldn’t look Kurogane’s way for more than a glance. The silence stretched between them, and Fai fidgeted briefly. “We should get back with Moko-chan and Syaoran-kun. Come up with a plan.”

Kurogane let out a breath through his nose. He couldn’t be too angry with Fai. This wasn’t the mage’s fault for one, and all of them were having trouble adapting. And he had a guess of just why Fai had trouble keeping his eyes his way. He tried to keep that in mind. “Let’s go.”

* * *

Out of all of them, Mokona was coping the best, and Kurogane was secretly a little jealous, though he was glad she wasn’t suffering. Syaoran had come to the same conclusions he and Fai had — and that he was going to be the one most likely to be able to get them all out. It made sense to Kurogane. Syaoran was well-versed in magic — had studied it much like Fai had — and was in a body suited for inter-dimensional travel. While Syaoran’s own body was probably capable, Mokona did magic instinctually, and probably would not figure out human magic fluently enough to attempt the strenuous spell before Syaoran beat her to it.

Kurogane’s teeth itched.

They were all tried, and so the meeting over a meal was short. There was no meandering conversation, just the makings of a plan and Fai’s best assurances that everything would be okay before they split back into their respective rooms again.

Kurogane idly tapped his fingers together, feeling nothing in the pads, only knowing the contact had been made by the pressure in his fingers and the confirmation of his eyes. It explained why the idiot was terrible with his hands and couldn’t patch a tear to save his life. Kurogane’s mind drifted back to Infinity, where Fai had offered up his vision as a price, and he wondered how the idiot would have meant to read with no sight and no sensation in his fingertips for braille. He also considered the way Fai touched him — long stroking motions, reaching through the top halves of his fingers, dragging along his skin so Fai could feel the pull of it.

“You really can’t feel anything, can you?” he asked so abruptly that Fai startled at the low pitch of his own voice. Fai’s answering laugh was uneasy.

“I was surprised at how sensitive your fingers are. It’s nice,” he said, answering by not answering. Kurogane only frowned at that. “I should show you how to wash my hair so you don’t damage it,” he continued, changing the subject.

“Is that okay?” Kurogane asked with some suspicion.

Fai looked in his direction, eyes closed. The body he was in did not lie as well as the one he was used to. “Why wouldn’t it be?”

Kurogane had thought they were past this kind of deflection, but maybe the unusual circumstances were making Fai rely on his old tricks for comfort. “You keep thinking about your brother.”

Fai froze, surprised as though Kurogane’s words had reached out and physically struck him, and Kurogane knew he’d hit the nail right on the head. Fai’s expression shuttered and he turned away, fidgeting again. “Cool water, shampoo mostly the scalp, and condition the ends.”

It was as much a confession as Kurogane was going to get from him, and it was enough. As Kurogane made to pass Fai on the way to the bathroom, he paused, placing a hand on Fai’s shoulder. If they were in their own bodies, he would have held him. He would have reached forward and folded Fai into his arms, using the whole of his body to shield him from the outside world until he could find a semblance of ease. But they were not in their bodies, and Fai was especially sensitive to his own shape right now, so Kurogane went for the more neutral action.

Fai reached up and touched his hand briefly, but didn’t look his way, and Kurogane continued on to make use of the shower. By the time he was done, Fai was curled up on the bed, asleep or feigning sleep, somehow managing to look small even in Kurogane’s hulking form. Kurogane could scold him for going to bed dirty another time, but for now, he prepared for bed and they slept that way, backs facing each other and neither sure how they would face the next day.

* * *

When Kurogane woke, he was still in Fai’s body and Fai was long gone, his side of the bed gone cold. If that was how the mage was going to play this, Kurogane thought sourly, this was going to be one miserable stay. The sun was higher in the sky than Kurogane normally got up, and he blamed it on Fai’s internal clock, but he got up and shoved the bed to one side of the room to practice his kata anyway, if only to have a sense of normalcy.

The familiar movements felt strange in this form. It wasn’t that Fai’s didn’t have the muscle control to handle it — quite the opposite — but with less bulk to move around, the motions were more fluid, almost a dance, and Kurogane had long since learned how to work around the limitations of his shoulder. Not having to constantly feel out that area for the first signs of over-stressing that would lead to a day or two of pain was nice, actually.

He was nearly finished when Fai bounded in, sweaty and with an armful of foods pilfered from downstairs. “Morning, Kuro-chan!” he called as he carelessly dumped the bounty on their bed and Kurogane watched the movement to see if Fai was favoring that shoulder as the mage babbled on. “You weren’t up for breakfast so I made sure to save you some. You gotta eat or you’ll be pissy all day, you know. Anyway, I’m gonna take a quick shower. Your body sure knows how to sweat, doesn’t it?”

Kurogane at least couldn’t smell the blood that would indicate Fai had really put his body through the ringer. All the same, he offered some advice as he continued the exercises: “Hot water will help.”

Fai started at the sound of his own voice again, but recovered quickly, if only a bit visibly awkward. “Well of course hot water will — ”

“I mean the shoulder,” Kurogane elaborated, trying not to get angry with the deflection. “If you let it sit under the spray a couple minutes the muscles will loosen up.”

“I know. I know how to treat sore muscles, Kuro-tan,” Fai admitted after only a little hesitation, voice gone quiet and solemn. Almost as though hearing himself snapped him out of the mood, he continued on with a bit more cheer: “And I had Moko-chan get a couple knots out before I came back. Did you know massage is one of her 108 secret techniques?”

Kurogane frowned at that, but there was nothing much he could do about it. What was done was done. “You shouldn’t worry the kids like that.”

“And you should let people worry about you once in a while,” Fai shot back, only to immediately try to smooth the remark over. “Sorry, that was — ” Fai didn’t clarify exactly what he thought the comment was before he changed tracks: “Is there anything special I have to do to clean.. that?”

Well, two could play the let’s-not-talk-about-it game if that’s what Fai wanted to do, Kurogane decided a bite sorely. Besides, there was a headache growing behind his eyes and he really did not want to get into a shouting match with the mage with it there. “Just water on the outside, no soap.”

“Got it,” Fai confirmed, gathering a clean towel in his arms and heading into the bathroom. “I’ll be right back.”

Kurogane finished his warm up and sat down for breakfast to find that most of what Fai had dragged back for him had been sugary monstrosities. He grumbled about it as he selected the plainest muffin from the lot and bit into it to find that he automatically made a face at the taste of it, almost as though his body read the flavor as bitter. Frowning, he set it aside and picked up a chocolate one instead and that was better. If this was what sweets tasted like to Fai, he could understand why that seemed to be all he ate.

On a hunch, he picked up the thermos and sniffed the contents — coffee, prepared just the way Fai liked it. Kurogane himself hated coffee, but something in this body seemed to relax a bit at even the smell of it. Gingerly, he took a sip to find that though it had cooled some, his taste buds delighted as the brew washed over them. No wonder Fai drank so much of this crap, Kurogane thought.

It was in this manner that he worked his way through another sweet pastry before his body started to feel comfortably full, and he was still sipping at the thermos when Fai emerged from the shower. “Make sure you drink all of that or you’ll get a headache later,” he offered, and the sound of it registered as an apology in Kurogane’s ears.

It was good enough for now, Kurogane decided. “How’s the shoulder?”

“Better,” Fai admitted, sitting close to Kurogane on the bed, though still leaving space between them. “Your routine is hard on it.”

“Life is hard on it,” Kurogane allowed. “I’ve learned to work around it.”

Fai hummed an acknowledgement as he picked up the abandoned plain muffin, not caring at all that it was already bitten into as he started to pick at it himself. “Moko-chan apologized that she couldn’t get your pain medication while in Syaoran-kun’s body. That’s why she offered the massage instead.” Kurogane sighed at that; he hadn’t meant for Fai to find out about it that way. The Tomoyo of Piffle had made sure he had a supply of it because she knew the limits of prosthetics and though Kurogane didn’t always need them, he had to admit they helped a lot. “I know you value your privacy. I would have asked you for one instead if I thought it was that bad, not gone to the kids. She just looked so guilty, so I let her.”

On a level, Kurogane had known that. He and Fai both had their secrets, though for completely different reasons, and he had no reason to believe Fai would just lay all his bare at the first opportunity. “You could have just skipped the kata,” Kurogane said instead.

“And let this sexy body go to waste? I don’t think so,” Fai said with a laugh in his voice before taking another bite from that muffin. “Your taste buds are weird.”

“Pot, meet kettle.”

Fai’s answering shove was playful, and that, Kurogane thought, was just fine.

* * *

The rest of the day was not so productive, though not for lack of trying. Fai tried to coach Syaoran through locating Mokona’s magical core after it was found that Mokona’s advice was not as helpful as she seemed to think. Leaving a world apparently relied on feelings of wanting to explore, pulling out stored objects relied on wanting to discover what was lost, and communicating with Yuuko and Watanuki relied on the desire to reach old friends. While these were no doubt helpful to Mokona, who obviously knew her own body inside and out, they didn’t help Syaoran learn how to access her magic with any emotions he felt, no matter how strong. When asked if she knew where her core was and how to reach it, she only said that Mokona’s core is Mokona’s core, and it’s always been there when she needed it.

Having gotten essentially nowhere, they retired to their rooms again after dinner. “Maybe we should try my magic after all,” Fai commented from his perch on the bed, a bit absently as if he was focusing on something else.

Kurogane scoffed at this. “You really think I’ll be able to pull that off when I don’t even use magic?”

“Of course you use magic,” Fai countered as if it was the most obvious thing in the world.

Kurogane thought he was being ridiculous. “Since when?”

“Always,” Fai provided, finally focusing on the conversation he was having. “Those sword attacks of yours aren’t just wind, you know. And if you couldn’t use magic, then how do you think you’ve been pulling your sword out of your hand all this time? You’re just used to having a conduit, that’s all. I can work with that.”

Kurogane sputtered a bit at that. “You can’t seriously think — ”

“We might not have any other options,” Fai continued, cutting him off. “If Syaoran-kun can’t even reach Moko-chan’s core, then that plan is shot, and Moko-chan doesn’t have the discipline to put Syaoran-kun’s body through a difficult spell like that without damaging it.”

“And you think I do?”

“I’m a little sturdier,” Fai said as if there was something amusing about that, “And you’ve got more discipline than the rest of us combined.”

Kurogane folded his arms, leaning against the wall as he considered. “I don’t like it.”

Fai stood then, crossing the room to him and running his hands up and down Kurogane’s arms in a gentling motion. He still was only barely glancing Kurogane’s way at every turn. “I don’t like any of this either, but we can’t stay like this forever. If nothing else, Syaoran-kun’s curse will force us to move on eventually.”

“What will happen if we can’t?”

“Nothing pretty, I’m sure.”

Kurogane hummed in thought at that. This really was an ugly situation. “What about the magic in my body?”

“There’s not enough to bring all four of us that way, I’m afraid.”

It really was a bitch of an ugly situation, but there was nothing Kurogane could do about it now that they were here. “Can’t hurt to try.”

“That’s my big guy,” Fai cooed, and Kurogane swatted at him lightly in irritation. Fai backed off then, resuming his position on the bed. “We’ll start tomorrow.”

* * *

The way Fai explained their plan in the morning was a much more gentler version than he’d given Kurogane. Syaoran and Mokona would work one-on-one, as they both knew their own bodies best, until either of them could perform any magic whatsoever. Meanwhile, Fai and Kurogane would work on alternative plans.

Fai, for his part, was patient with Kurogane as he tried to get him to so much as focus some energy to the tip of his finger. They broke for lunch and continued to no avail, and by the time dinner came along, it was discovered that neither side had made any progress. If Fai was frustrated, he didn’t let it show, and somehow that only made Kurogane more irritated. Just the night before, Fai had seemingly understood they were working under a time limit with possible dooms-day implications, and yet the very next day, he was acting as though everything was right as rain.

If Fai had figured out how to lie so fluently in Kurogane’s body, Kurogane was going to wring his neck.

Still, he held his tongue until they were safely back in their rooms, if only to maintain face in front of the kids. “Why are you so calm about this?” he blurted as soon as the door was shut.

“Will getting angry about it help?” Fai asked lightly.

“It might!”

Fai hummed to himself, gathering up the necessary items for a shower. “We still have time, Kuro-chan. We can afford to be patient.”

“How do you know that?” If Fai was keeping secrets from them now of all times, then Kurogane wasn’t sure he could actually beat them out of him with the body that he had.

Fai only shrugged, though. “Just a hunch. Yuuko-san was always talking about coincidence and inevitability. Well, mapping the dimensions, we would have had to land here someday, right? So, there has to also be a way we can leave safely. Have some faith, Kuro-sama.”

“Faith?” Kurogane scoffed, “Coming from you of all people?”

“Coming from me of all people,” Fai confirmed without any heat. “We’ll figure this out, I promise.”

Fai didn’t often promise things, and Kurogane was not about to doubt him on one yet.

* * *

_ “Kuuuuro-chaaaaaaan!” _

Kurogane was startled into full alertness by the sight of his own face grinning like the cheshire cat inches from his own. Fai just barely dodged a fist to the head as Kurogane jumped back into a hunched position before the rest of his head caught up with him and overrode decades of trained-in instincts. Fai, for his part, did not look discouraged in the least. “What the  _ fuck _ , mage?”

None of the maddening glee had fled his features at Kurogane’s reaction. If anything, he almost seemed more enthused. “I figured it out.”

* * *

Several minutes and a coffee later, when Fai’s body permitted the kind of complex thought that the conversation clearly required, was when Fai launched into his excitable explanation. “The trouble with cores is that everyone’s is a little different. They have to be reached in different ways, they are capable of producing different types of magic, and it seems they can even rest in different places in the body. Now, I knew yours would require discipline to reach because you’re you, obviously, but I couldn’t figure out why I couldn’t quite reach it until I finally realized I was reaching into my stomach where mine is. But where mine is a bit up and to the left, you’re a more central and balanced person, and when I realized that and started looking for your core elsewhere, it actually wasn’t so hard to find. Now, do you know where yours sits?”

Kurogane opened his mouth to say that no he didn’t, but didn’t have the chance to say anything because before his eyes, Fai was activating the spell in his hand, drawing out Kurogane’s sword with ease. “Right behind your belly button! That’s just like you, having it pretty much dead-center in your abdominal muscles. It should have been so obvious! I can’t believe I didn’t think about it until just a little while ago. By the way, did you know your body needs an inordinate amount of caffeine to last a whole night without adrenaline? You must be getting old, Kuro-rin.”

Fai dismissed the sword with a wave of his hand while Kurogane processed what he said. “Ok, so you can use my magic. What does that actually change?”

Fai’s voice then was so assured that Kurogane found himself convinced without even trying: “Everything.”

* * *

Fai was a bit more subdued when they made it downstairs to meet with Syaoran and Mokona. He only said they were making progress and that neither of them should be discouraged. After dropping the hint that the cores they were looking for may be in different places than they expected, Fai had them break ranks to separate into pairs again. The moment they were out of sight of the kids, Kurogane caught him around the elbow and pulled him to a halt. “Why didn’t you tell them you can use my magic?”

Fai gingerly pried Kurogane’s fingers off his arm. “Because my plan still might not work, and I don’t want them to get complacent, just in case.”

It made sense, but Kurogane still did not like it and he said as much, though Fai, being Fai, brushed off the comment like it was dirt on his shoulder. They spent the first half of the day trying to get Kurogane to so much as reach Fai’s magic while Fai seemed more content with testing the abilities of Kurogane’s. This lasted until lunch, where Fai absolutely insisted Kurogane eat a full and balanced meal before they continued.

This time, they left for a field far outside of where they could be expected to be seen, and Fai immediately stepped up to Kurogane and placed his hand on Kurogane’s stomach, over his lower ribs on the left side, but too low to be targeting the heart. Kurogane allowed the touch with a raised eyebrow. “What are you doing?”

“Giving you a jumpstart,” was the cheeky reply, “Now, concentrate on the very tips of your fingers.”

With an exasperated sigh, Kurogane did as he was told as if they hadn’t been trying something like this all morning, but this time, it was a little different. After a moment, the space Fai held his hand began to grow just a little warm and vaguely itchy. Kurogane ground out “mage” like a warning, but Fai was unperturbed as the space grew hotter and hotter and Kurogane was sure if they waited much longer his skin was going to burn, when suddenly it was as though a plug had been inserted in a socket and the tips of his fingers glowed blue.

Kurogane started at the abruptness of it all, suddenly able to not just feel clearly, but connect with the nearly infinite power Fai’s body had within itself, like the ability to reach it had suddenly made it real and nearly urgent, gathering within his hands just begging to be used on something —  _ anything _ — to be rid of the sensation of being so full of power that it could rip him apart at the seams. Fai broke his connection with him, but it was almost as if he was on a feedback loop and now that he could access it, he didn’t quite know how to stop and — shit — he really was going to blow Fai’s body apart at this rate but it was completely beyond Kurogane’s control and — 

“That’s enough for now,” Fai commented calmly. His hand circled Kurogane’s wrist and it was as if the feed had been severed and Kurogane almost collapsed in relief. He settled for leaning against Fai for support instead, just for a moment, for soon Syaoran and Mokona were rushing over the hill and Kurogane was shoving off to save face.

“Is everything alright?” Syaoran asked almost frantically. “We felt a surge of power and — ”

“Everything’s just fine,” Fai assured them with a laugh in his voice. “Someone just needs to learn a little discipline, that’s all.”

Kurogane couldn’t even be angry at the jibe. He hadn’t trained to handle something like that, and it had been well beyond his ability to control, much like a child thrown into the deep end of a pool for the first time. Now that he had felt it, and just how easily it could run completely wild, he was sure that he could and would do better for the next time.

He had to.

* * *

Instead of more training, though, Fai shooed him off to their room to get some rest, citing the strenuous activity and his own body’s limitations. Kurogane thought the excuse was bullshit, but a nap was still welcome, so he didn’t fight the coddling — not too much anyway. He backed off when Fai made the point that he could possibly provide the same jumpstart for Syaoran and Mokona as he did for Kurogane, and that at least sounded like progress. Sure, Kurogane could access the raw power, but he wasn’t versed at all in using it. Letting Mokona or Syaoran ferry them off into the next world was still the safer option.

Which was all well and good, until Kurogane woke up from his nap and felt out where Fai was, only to find he was not in the vicinity of Mokona and Syaoran whatsoever. In a snit, he threw off the bed sheets and stalked off to find the mage downstairs, hunched over a notebook that was covered in script Kurogane couldn’t read and diagrams he couldn’t make sense of. Fai perked up at the sound of Kurogane storming in, but didn’t make any effort to hide his work whatsoever, likely knowing that even if Kurogane could see it, he wouldn’t be able to understand it.

“Good morning!” Fai called while Kurogane was still halfway across the room, not bothering to look guilty in the slightest.

“I thought you were off helping the kids,” Kurogane said by way of accusation.

“I am,” Fai said with a bit of a lazy smile.

Kurogane was of half a mind to launch Fai clear across the room. “By doodling?”

“By working on some theory regarding spatial displacement and interdimensional doorways.”

Ok, maybe he was being productive, Kurogane admitted only to himself as he sank into a chair, rubbing at a temple as he felt the beginnings of a headache. “Can either of them reach their cores yet?”

“Not yet,” Fai said as if it was of no consequence at all.

That only pissed Kurogane off even more. How could a bunch of theory help any of them if nobody who had a chance of using it could even use their magic just yet. “How the hell is theory going to help that?”

Fai glanced up at him momentarily, only to return to his work. “Go get some coffee, Kuro-tan.”

Kurogane sputtered indignantly a moment at the sheer audacity of Fai’s command. “I am not your maid!”

“Go get  _ you _ some coffee,” Fai amended. “You have a caffeine headache. Drink some and come back when you’re feeling better. I’ll explain it then.”

It was a compromise he could live with, even if Kurogane wasn’t happy about it as he stomped off, muttering uncomplimentary things under his breath about sneaky magicians and their flighty tendencies. Luckily, the cafeteria still had some fresh enough coffee, and Kurogane dumped half its weight in cream and sugar into the mix until it became something his taste buds would find appetizing. He was forced to admit that Fai’s suggestion made sense when some of his tension eased at the first sip, as if his body knew relief was on its way and could stop sending pain signals through his brain to force him into action. He drank half the mug and topped it off before heading back into the study that Fai had commandeered for the afternoon with a mug of tea for the mage, which he set down none too lightly. “Talk.”

Fai sat up from his hunched position and took a bracing sip of the tea as if still weighing in his mind what to say and how to say it, and Kurogane was starting to get sick of his evasive tactics. Finally, Fai brought the mug down and faced him, looking him directly in the eye for what may have been the first time since they originally landed in this world. “The problem is that Moko-chan isn’t human. It’s entirely possible that it is completely impossible for the two of them to use each other’s magic in this lifetime. So if neither of them can help us leave, that means we need to somehow use my magic to do it, because even if your body has enough magic, I’m pretty sure the strain would drain it completely to the point it would never regenerate, if not kill you when it runs out and relies on your life energy instead to complete the spell, and that would be unacceptable.”

None of this was new information — nothing Kurogane hadn’t already suspected even if he didn’t rightly know it was true in fact. Fai was still deflecting. “So what does that have to do with this?” he asked, indicating the notebook with a vague motion.

“I’ve been trying to work out how we can use my magic without making you use it,” Fai answered with half a shrug. “It’s been a long time since I’ve had to siphon from someone else, so I’m making sure I’ve got all the theory right before we try to test it. This — ” he said, indicating a complex vertical diagram “ — is a map of how energy typically moves through a body at rest, and these figures here indicate the pull of forces that make up interdimensional travel spells, which affect the flow of energy. Different spells impact different parts of the body, and so when doing them, one would have to compensate for those pulls or risk physical damage. Typically, one is in the body that is providing the energy and by the time one works up to that level of spell-crafting, one is familiar with those forces and can counter them instinctively. However — ”

“Being separate, you wouldn’t feel those forces, and someone could get torn to ribbons,” Kurogane deduced.

“Exactly,” Fai said, nodding. “It’s dangerous, so I’ve got to make sure we get it right the first time.”

Kurogane frowned. It was a solution, but not one he liked at all. “Are you sure my body will be able to take it?”

“Your body will be fine,” Fai assured him, almost too easily, “You’ve always been better with a conduit.”

Which was the one that was actually more at risk, Kurogane knew. He also knew that that fact would not change Fai’s mind about this plan. “In this case, your body.”

“Exactly.”

Kurogane frowned, considering. Fai was putting his own body at great risk, and though it wasn’t a certain death, he still wasn’t comfortable with how easily Fai would throw himself up as the sacrifice when things got a little hairy. “I don’t like it.”

“I know,” Fai admitted. “And if I thought there was another way, I’d consider it, but with how quickly you were overwhelmed this morning — ”

“Mage,” Kurogane growled out, but Fai was swift to cut him off.

“I’m just saying it’s not likely you’ll be able to master a high-level spell like this when you can’t even access my magic without it spiralling out of control. I’m sorry, Kuro-puu, but that option is off the table.”

Kurogane couldn’t rightly say that Fai was out of line with that one. Usually, someone had to work hard and know a great deal about magic before they could ever hope to get anywhere near this level of raw power, but these weren’t usual circumstances. In his current state, Kurogane was not much more than a risk to himself and everyone else. Still, there had to be better options. “And you can’t link with the kid or the manjuu?” At least at their lower power levels, the risk would be lower.

Fai shook his head softly. “Not unless they can reach their cores.”

“Which they can’t,” Kurogane concluded. “Shit.”

“Indeed.”

Kurogane huffed out a softer breath this time. “So when do we try this?”

Fai, for his part, didn’t look the least bit ruffled. “I’d like to start with some smaller things first thing tomorrow, if you’re up to it.”

Kurogane doubted he’d ever really be up to it — just the thought of them potentially damaging Fai’s body beyond their ability to repair made him feel sick, even though they were apparently starting from the bottom. Still, it would have to be done; he couldn’t argue that. “Yeah, alright.”

Fai reached under the table and squeezed his hand, and when Kurogane thought back to the action a few days later, it was then he should have realized that Fai was still hiding something important from him.

* * *

“So, have you had the chance to use it yet?” Fai asked after dinner with a lewd glance over his shoulder when they were safely back in their room, Syaoran and Mokona none the wiser to the change in plans.

“Use what?” Kurogane asked with some suspicion.

“My penis,” Fai replied, as it was the most obvious thing in the world. When Kurogane didn’t respond immediately, he pressed on. “Come on, you can’t tell me you aren’t at least a little curious.”

Kurogane’s face was as red as it could get, but he was not going to acknowledge that in any way. “When was I supposed to have time to do that?!”

Fai scoffed lightly at that. “You’ve had plenty of time! We have time now, if you want,” he added, voice dropping into Kurogane’s lowest registers for the first time since he started occupying that body.

Hearing his own voice talk like that — seeing his own face looking at him like that wasn’t really doing anything for Kurogane in that department however. “I can’t have sex with myself! It’s weird.”

“Then don’t,” Fai offered, a bit too lightly, but thankfully pitching his voice back up so he at least didn’t sound as Kurogane-like. “I can step out and have a drink, or — ” he slipped behind Kurogane running a hand up Kurogane’s chest in the motion “ — maybe I can help from back here. I know all the  _ really good _ spots,” he emphasized by pulling back on Kurogane’s hair, which he had to admit, felt nice. Kurogane neither accepted nor rejected the notion, so Fai gave it one final push. “This might be your only chance; you shouldn’t waste it.”

“Fine!” Kurogane gave in, voice almost a squeak that he distinctly did not acknowledge as he chucked off his shirt. “Just don’t — ah — ” that hand was back in his hair and Fai’s body really, really did like that “ — don’t talk.”

Fai when he spoke this time was with a breathless whisper scant inches from Kurogane’s ear and — wow — he was going to have to do that to Fai the very next opportunity he got: “I can do that.” Then, he was pressing Kurogane back with one wide hand splayed across his chest and biting into the lobe of the ear he was breathing into, and that sensation went straight to Kurogane’s groin. He’d never had the chance to appreciate their size difference from Fai’s perspective, and this close, he felt surrounded but not crowded or caged. It was more as though Fai could wrap him up and keep him safe by shielding him from the eyes of the world, and Kurogane had never thought anyone would be large enough to instill such feelings in him. It was one of the things that had kept him going in his own body — that he towered over everyone he met to the point they couldn’t dare disrespect him — but here in Fai’s, he was smaller, more vulnerable.

He hadn’t realized that the vulnerability could feel good in the right hands.

And right hands they were. Fai expertly sought out every spot that could drag a groan out of him, lips attaching to every sensitive spot on his neck and not letting go until Kurogane was sure those points would bruise. Those hands scratched down his chest and played his nipples like they were an instrument that Fai had mastered long ago — and Fai probably had — until Kurogane was experiencing the unfamiliar sensation of his cock filling and rising to the occasion. He didn’t miss the way when Fai’s hands dragged further down his body that they easily spanned the width of it — something that forced a moan from his throat — and he began to understand just why Fai put up with the amount of manhandling that he did.

Those clever hands found the line of his pants and teased along the hemline, massaging his hips and once or twice dipping underneath in teasing motions until Kurogane reached forward to undo the clasp and shuck them off, releasing his dick from the uncomfortable cage and allowing it to spring forwards and up.

Instead of heading straight to the goal, though, Fai rubbed up and down Kurogane’s thighs, slowly massaging their way inwards in a way that had Kurogane straining to get the attention to where he wanted it most, though he gamely kept his own hands clutched on Fai’s forearms, trusting that Fai knew how to work the most pleasure from this body possible and able to clamp down on his self-control for just a little bit longer.

It seemed the more sounds Fai could work from him, the more Kurogane became worked up, because these were the sounds of Fai’s body. Every gasp and cry was music to Kurogane’s ears, even though he knew they were coming from his own throat, but his mind was trained to become excited at them all the same. As the sounds of Fai became increasingly desperate, Kurogane found himself bucking into the air, seeking any friction at all, and finally, one of Fai’s hands reached in to cup his balls, a finger unerringly finding the perineum, and Kurogane yelped at the unexpected contact.

It was good, almost too good, and for a moment Kurogane thought he’d cum without having ever been touched, but Fai reached back to lick his palm before coming forward again to grasp Kurogane’s shaft. “Fai!” Kurogane cried, and he wasn’t even bothered by the low moan behind him as Fai began to work up and down, twisting at the head to smear the pre around in a way that had Kurogane fighting to thrust up, despite the arm that was playing with his balls pinning him down.

It didn’t take much longer from there. Kurogane knew he was babbling some nonsense on a feedback loop of Fai’s voice — the more he talked, the more he heard, and the more turned on he got by it, and maybe there was something sick about getting off to a voice you possessed, but at that point, Kurogane didn’t care. All that mattered was that he was hearing Fai come apart as he was taken apart and  _ shit _ Fai really did enjoy those dexterous hands, and then Kurogane was cuming like he never had before in his life, and still Fai worked him through it until Kurogane finally slumped in his arms, panting like he had run a marathon and feeling thoroughly completely sated.

Fai’s arms shifted to hold him more securely, tipping them both back and sideways until they were both lying on the bed, Fai spooned up behind Kurogane. It was a few moments before Kurogane’s brain recovered sufficiently to even attempt a comment. “That was — ”

“Liked it?” Fai asked, again deep in Kurogane’s voice, and Kurogane did not mind.

“Oh yeah,” he said, breathlessly.

“We can do that again if you like in a bit,” Fai offered, nuzzling into Kurogane’s hair. “You still have a prostate to explore.”

A sudden thought had Kurogane turning in Fai’s arms. “What about you?”

“I, ah,” Fai began a bit awkwardly. “That is, I found out I’m not really comfortable exploring.. that in the shower the other day.”

Kurogane couldn’t say he didn’t understand, so he didn’t push it, instead just relaxing back in the circle of Fai’s arms and letting himself be surrounded and held. Who knew if he’d ever feel the comfort of being covered so completely ever again.

* * *

The next morning, Fai’s body actually allowed Kurogane to wake up with Fai — though this probably had more to do with how close they were laying than Fai’s internal clock — and so they both grabbed breakfast together and ran through the kata together, and afterwards, when Kurogane was massaging out the knots that Fai had somehow managed to accumulate on Kurogane’s body much the same way he tended to on his own, things finally began to feel a bit normal. Sure, they were in the wrong bodies, and it was weird not being the largest guy in the room, but it felt as though whatever distance had grown between them at the change had shrunk just a little, and Fai was beginning to fight back the gut reaction he felt at seeing his own body from another perspective.

The group meeting was short and to the point once again. Syaoran and Mokona would keep trying while Fai and Kurogane tested out an alternate plan. If the kids were discouraged, they gamely didn’t show it as they separated off again, and Fai and Kurogane took off for that isolated field once again.

“Did you see Moko-chan’s earring?” Fai asked as they crested the final hill.

“Yeah.” The glow meant they were meant to be leaving. “We don’t have much time.”

“We’ll be ready,” Fai assured him, and the sound of it was only a bit strained. Kurogane could understand that, with them being on a shrinking timetable. When they reached the center of the field, Fai grabbed his hand, and Kurogane could feel a connection forged almost instantly. Fai’s serious face was at home on Kurogane’s features when he issued the warning: “Tell me immediately if anything begins to hurt.”

Fai waited for Kurogane’s nod before he started drawing in the air. First it was just one simple glyph, one that generated nothing more than a breeze, and Kurogane felt almost nothing as the magic was siphoned out of the body he was in into the one he was meant to be in. Gradually, Fai worked his way up to more difficult spells, bringing forth bubbles, then flames in his hands, then a gale, then a shield, then finally a rudimentary attack before he stopped entirely, releasing Kurogane’s hand and searching Kurogane up and down with his eyes, checking for damage. “Relax, mage, I barely felt it,” Kurogane said with complete honesty.

“The theory’s sound then,” Fai commented, though he didn’t seem entirely present as he did, mind working over the next several steps in what he planned to accomplish. “Now we’ll try the reverse, and I’m going to need you to stay relaxed for this.”

“Alright,” Kurogane replied, not uncertain about his ability to relax, but more of what Fai planned to do, and Fai took up Kurogane’s hand in one of his own.

“One finger out for me?” Fai directed, and Kurogane did so. In the space of a breath, Fai restored the connection Kurogane had with Fai’s core, but this time it felt controlled, less of a deluge and more of stream, and Fai was moving his hand manually, writing in the air on Kurogane’s behalf and stemming the flow in precise increments until another shield was made, this one a bit stronger than the one Fai had created moments before. Fai dropped his hand and the connection was severed, causing the shield to dissolve as Fai moved in front of Kurogane, once again checking him up and down. “How did that feel?”

“More controlled than when I tried it,” Kurogane admitted while Fai continued to fret.

“No pull anywhere in your body? Nothing feeling out of place?”

“Everything felt fine,” Kurogane asserted, keeping a tight hold on his temper at being fussed at.

Fai stepped back a pace, seemingly placated. “Alright. Let’s keep going, then.”

Fai continued switching back and forth between having his own body and Kurogane’s channeling the spells, gradually increasing the power and control needed, and through it all, Kurogane hardly felt a thing. He could feel as the magic lessened incrementally where it was stored, and he could feel when the connection was made in either direction, but for hours, nothing else really registered until the sun was high in the sky and Fai was putting together something intricate and a little time-consuming, when Kurogane felt a pull, not in the shoulder he was occupying but somehow the one in his own body next to him, and that was when he spoke up. “Stop.”

Fai, to his credit, complied immediately, anxiety bubbling up to the forefront. “What is it? Are you hurt somewhere?”

“Not me, you,” Kurogane muttered, reaching forward to Fai’s aching shoulder. “You’re over-taxing it.”

“And you could feel that?” Fai asked with a touch of awe, not rejecting the touch. Kurogane nodded, and Fai’s mind went elsewhere again. “Interesting. But nothing from you?”

“Nothing at all.”

Fai was quiet a few moments, and Kurogane used that time to work out the knots that had formed until Fai came back to the present with a decision. “We should break for lunch.”

* * *

The question came suddenly and Kurogane was grateful only that the kids weren’t around to hear when Fai asked: “If you could, would you keep that body?”

Kurogane, in a great show of self-control, did not spit out his bite of sandwich, though he did cough once or twice in recovery to clear his throat, during the span of which Fai only barely glanced his way. “What the  _ fuck _ , mage?”

Fai shrugged as if the matter was nothing at all. “I was just thinking with the dysphoria and the shoulder, you might like my body a little better, that’s all.”

“And I could keep it and subject you to those instead? Not a chance,” Kurogane asserted, swiping up his drink and considering the argument won, a bit prematurely.

“I could manage,” Fai’s voice continued to be light. It didn’t help stem Kurogane’s rising temper.

“You shouldn’t have to.”

“Nobody  _ should _ have to,” Fai countered with a roll of his eyes.

“That doesn’t mean you need to offer to trade your body for mine just because you think I might think it’s a little nicer. That’s horse shit,” and he punctuated that statement by taking another bite of his sandwich, tearing his own eyes away if only to give himself a chance to cool his rising temper. “Can’t believe I still have to talk you out of self-sacrificial bullshit.”

Fai put his fork down haughtily, visibly making an effort not to fidget. “Maybe I like being taller. Your body isn’t all bad, you know.”

Kurogane knew it wasn’t all bad, but in the end that wasn’t the point. “I’m not accepting any body you can’t look at me in,” he replied, a little quieter than he intended, but the point made its way across the table to Fai anyway, and the mage nodded with eyes a little wet.

“Okay.”

* * *

After lunch, Fai searched out Syaoran and Mokona while Kurogane nursed the last of his coffee. Something about that awkward conversation just a few minutes back had him doubting that Fai had really given him all the details of what he had planned out. There was something that he was missing in all this, and the idea of that ate away at his own resolve just a bit. What if this plan really would destroy the mage in the end? How could he be sure the man wasn’t just acting in what he felt were the best interests of everyone else involved? How could he be certain that Fai really had changed for the better and was above that kind of nonsense, even when the situation was potentially dire?

The answer was that he couldn’t know, not really — not until the deed was done. And so the real question was could he trust Fai with Fai?

Kurogane drained his cup and made a choice.

* * *

In the field, Fai gathered all of them close and stepped behind Kurogane, directing his finger in the air just as he had in the morning, and giving a gentle push to encourage Kurogane to walk with him around until the glyphs finally closed into a circle.

Strangely, Kurogane didn’t feel a thing at first. The magic didn’t resonate with his body at all as the spell was drawn, almost as if the power needed for it was so negligible as to not exist. But then the circle closed and the runes started falling in, and Fai slapped his hand down on Kurogane’s stomach, making the connection with the core instead.

That was when Kurogane felt, though at a distance the same way he had felt when Fai’s shoulder started to twinge scarcely an hour ago. The forces in Fai were pulling, churning around and tugging at hidden spaces, and at first it was merely uncomfortable, but as they were on the brink of departing the world, Kurogane registered the pain, and that was when Kurogane tried to pull Fai’s hand off of him, but the damn thing wouldn’t budge. Of all times for Fai to finally use the increased strength against him, Kurogane thought this could probably be the worst. “Dammit, mage, let go!”

Fai only held tighter, shaking his head mutely with his mouth clamped shut, and then Kurogane felt a ripping sensation, like something was tearing at him now, and he felt lost and untethered in the void between realms, no sensation apparent to him at all for the few moments before his awareness left him.

* * *

Kurogane landed and his shoulder fucking hurt so his hand went to it automatically, and it didn’t take long for it to register that it was his shoulder and not Fai’s. It didn’t take long to realize that he wasn’t a part of any pile once again and his eyes shot open to see Syaoran and Mokona lying a few paces away, and there was a brief moment of panic where he didn’t see Fai, but just then there was a groan behind him, and Kurogane flipped over to see Fai picking himself up into a seated position gingerly, hissing in a breath between his teeth. “Mage?”

“I’ll be fine,” Fai assured him through gritted teeth, though it wasn’t as reassuring as Fai probably meant it to be.

Kurogane’s sigh was long suffering as he sat up and leaned in Fai’s space. “Where are you hurt?”

“Nowhere physical,” Fai admitted, and that really wasn’t nearly as reassuring as he had meant it to be, and Kurogane crossed his arms, pinning Fai with the full force of his glare.

“Explain.”

Fai’s smile was uneasy, but completely Fai nonetheless. “Well, when you felt your shoulder this morning — a wound you have a deep connection with — I realized the wounds that could be generated by attempting interdimensional travel unprepared might not be physical but spiritual, in which case — ”

“In which case you thought you were the better target,” Kurogane ground out, and if Fai wasn’t injured already Kurogane thought he might have beat him senseless.

“I am,” Fai asserted. “More magic, more capable of withstanding the damage, and more likely to heal quickly.”

Kurogane could smell his bullshit from a mile away. “And do you know you would heal?”

Fai was saved from answering when Mokona bounced over. “Mommy will heal! Soul healing is one of Mokona’s 108 secret techniques!”

“That’s right,” Fai cooed, scooping Mokona up with both hands and nuzzling her close, certainly not using her as a shield against Kurogane’s wrath.

“That was still dangerous, Fai-san,” Syaoran complained. “If your soul had been destroyed — ”

“I knew it wouldn’t be,” Fai cut in with an air of absolute surety. “I had warmed Kuro-chan up with my magic all morning. I’ve jumped between worlds before; I know what it takes. And even if I couldn’t handle it completely, I could still take most of it, and if it got too dangerous, I could have dropped out and let Kuro-pii take the rest.”

“Oh really?” Kurogane asked, still not entirely convinced.

“Of course! I couldn’t leave you to raise two kids on your own like that. What kind of monster would I be? Besides,” Fai leaned over conspiratorially, already visibly in less pain, as if the short argument was a healing all on its own, “If I really did die like that, you’d just drag me back by the hair and daddy’s shoulder’s already angry at him enough for one day.”

Mokona gasped between them, even as Kurogane felt his cheeks growing hot. “Daddy’s in pain?” And as Mokona spat the familiar pill bottle out into Fai’s waiting hands, Kurogane couldn’t even find it within himself to be mad about it. Fai was alive — they all were alive — and back in the bodies where they belonged, hopefully for keeps.

That didn’t stop Kurogane from dipping forward, breath washing over Fai’s neck and raising goosebumps where the marks lingered as his breath pitched low so the kids wouldn’t hear his not-so-idle threat. “I am going to drag you by the hair tonight and you are going to enjoy every minute of it.”

Judging by Fai’s reaction, he wasn’t going to mind one bit.

**Author's Note:**

> [More notes](https://deforrest-bergan.tumblr.com/post/627548362403610624/swapped-kien-rugastelo-cein-tsubasa)


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